If you’re queuing for a Fortnite tournament (for example, the All Valley Cup), and you receive an error message that says, “Failed to query for tournament rules”, then the best way to fix it is to quit the game, then try again in 15 minutes. If you’re queuing for a long time, but you don’t get this message, then you’ll just have to be patient. Don’t restart, as this will just send you to the back of the queue.
It’s also worth checking that the tournament you’re entering is actually active, and that you meet the entry requirements. To find out when a tournament starts, start Fortnite and go to the Compete tab. Here you can see when all scheduled tournaments are due to start. Scroll to the left to find the tournaments starting soonest. You can check the details of each event and, if there is a tournament in progress, you can enter.
In order to enter a tournament in Fortnite, your career Epic Account level must be at least 50. This is different to your Season Level, and can be found on the Career tab. You must also have Two-Factor-Authentication (2FA) enabled, which can’t be done in-game. Follow this link to set up Two-Factor-Authentication on your Epic Account. You may need to set up an account first, if you haven’t already.